Lizzy Caplan is officially an engaged woman!

The actress' rep tells E! News that her boyfriend Tom Riley proposed in May, just three months after making their red carpet debut as a couple.

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The Masters of Sex star first sparked engagement rumors when she was spotted on a shopping trip with her fiancé Friday sporting a diamond ring on her left hand.

lizzy caplan tom riley getty images

The 34-year-old and her actor beau met in January 2015 while she was filming in London, but didn't confirm their romance until the 2016 Prague Opera Ball in February.

The exciting news comes just days after Lizzy's Mean Girls co-star Daniel Franzese announced his engagement to partner Joseph Bradley Phillips.

Scroll through the gallery below to see what more of the supporting actors from Mean Girls look like now!